[Protein trafficking in the secretory and endocytic pathways].
Explore the source record for details and available documents.
Biological Transport↗
Biomedical subjects
H Ohno
Publications and source records attributed to H Ohno.
[Relationship between streptomycin susceptibility and rpsL mutations of Mycobacterium tuberculosis strains].
The relationship between streptomycin (SM) susceptibility and rpsL mutations of Mycobacterium tuberculosis strains was studied. Of 18 clinically isolated SM-resistant M.tuberculosis strains, mutation was suspected in 9 strains (50%) with SM MICs of > or = 256 micrograms/ml by PCR-single strand conformation polymorphism targeting rpsL gene. On the other hand, using PCR-direct sequence method, amino acid substitution caused by single nucleotide point mutation in rpsL gene was demonstrated in 11 out of 18 strains (61%). The same amino acid substitution at codon 43 (Lys-->Arg) was observed in all 11 strains with SM MICs of > or = 256 micrograms/ml. In addition, PCR products obtained from these 11 strains could not be cut by a restriction enzyme, Mbo II, while H37Rv strain and the other 32 strains with SM MICs of < 256 micrograms/ml were cut into 2 fragments. In conclusion, our results suggest that highly SM-resistant M.tuberculosis strains with MICs of > or = 256 micrograms/ml could be rapidly and easily detected by the restriction enzymatic method.
Antibiotics, Antitubercular↗
[Allogeneic peripheral blood stem cell transplantation for multiple myeloma].
We report here with a 46-year-old man with refractory multiple myeloma receiving allogeneic peripheral blood stem cell transplantation from his HLA-matched brother. The preparative regimen consisted of TBI (12Gy), VP16 (15 mg/kg) and cyclophosphamide (120 mg/kg). GVHD prophylaxis consisted of cyclosporin A and short course of methotrexate. The donor received G-CSF at 10 micrograms/kg/day for 5 consecutive days and underwent leukapheresis on days 5 and 6. The neutrophil recovery to 500/microliter and platelet recovery to 20,000/microliter were day 12 and day 15, respectively. The patient is currently well with no GVHD or graft failure and a complete donor's chimerism.
Hematopoietic Stem Cell Transplantation↗
Lengthening of the lower limbs in patients with achondroplasia and hypochondroplasia.
Ten years of experience in lower limb lengthening achieved in 35 patients with achondroplasia and seven patients with hypochondroplasia is reported. A uniform method of callus distraction (callotasis) was used in all cases, although the order of lengthening of each bone differed among the cases. The mean age of the patients at the time of first operation was 14.5 years; at followup, the mean age was 18.8 years. The mean lengthening achieved in the femur was 7.2 cm (range, 4.5-12 cm) and in the tibia 7.1 cm (range, 4.5-13 cm). More lengthening was achieved in the more recent cases. The function of lengthened limbs, evaluated by physical strength tests, was better at followup than before lengthening in the growing children, although the mechanical axes of the lengthened bones were not necessarily in correct alignment.
Achilles Tendon↗
The t(9;14)(p13;q32) chromosomal translocation associated with lymphoplasmacytoid lymphoma involves the PAX-5 gene.
The t(9;14)(p13;q32) translocation is associated with approximately 50% of lymphoplasmacytoid lymphoma (LPL), a subtype of B-cell non-Hodgkin's lymphoma (NHL). We cloned the chromosomal breakpoint of der (14) from an LPL case (1052) and showed that it involved a junction between 9p13 and the switch micro region of the Ig heavy chain locus (IgH) on 14q32. Using a YAC contig spanning 1.5 megabase (Mb), we determined that the 9p13 breakpoint in one case (1052) mapped within a 270-kb restriction fragment containing two previously reported 9p breakpoints associated with a alpha-heavy chain disease case (MAL) and KI-1 positive diffuse large cell lymphoma (DLCL) cell line (KIS-1). The same fragment also contained the PAX-5 gene which encodes a B-cell specific transcription factor involved in the control of B-cell proliferation and differentiation. The breakpoints of KIS-1 and 1052 were mapped within the 5' noncoding region of PAX-5, while the 9p13 breakpoint of MAL mapped 230 to 270 kb upstream to PAX-5. In all three cases, the translocation caused the juxtaposition of the PAX-5 gene to the IgH locus in the opposite direction of transcription. When compared with six other DLCL cell lines lacking t(9;14)(p13;q32), the KIS-1 cell line showed an 11-fold overexpression of PAX-5 mRNA and a significantly reduced expression of the p53 gene, which is normally regulated by PAX-5. Moreover, metaphase and interphase fluorescence in situ hybridization (FISH) analysis using a YAC clone spanning 1 Mb including the PAX-5 as a probe identified chromosomal translocations in 5 of 7 cases carrying 9p13 translocations. These findings suggest that the PAX-5 gene is the target of the t(9;14) in LPL whereby its expression may be deregulated by juxtaposition to IgH regulatory elements, thus contributing to lymphomagenesis.
Aged↗
Structural determinants of interaction of tyrosine-based sorting signals with the adaptor medium chains.
Many integral membrane proteins contain tyrosine-based signals within their cytoplasmic domains that mediate internalization from the cell surface and targeting to lysosomal compartments. Internalization depends on an interaction of the tyrosine-based signals with the clathrin-associated adaptor complex AP-2 at the plasma membrane, whereas lysosomal targeting involves interaction of the signals with an analogous complex, AP-1, at the trans-Golgi network. Recent studies have identified the medium chains mu2 of AP-2 and mu1 of AP-1 as the recognition molecules for tyrosine-based signals. We have now investigated the structural determinants for interaction of the signals with mu2 and mu1. The position of the signals was found to be an important determinant of interactions with mu2 and mu1; signals were most effective when present at the carboxyl terminus of a polypeptide sequence. Another important determinant of interactions was the identity of residues surrounding the critical tyrosine residue. Mutation of some residues affected interactions with mu2 and mu1 similarly, whereas other mutations had differential effects. These observations suggest that both the position and the exact sequence of tyrosine-based sorting signals are major determinants of selectivity in their interaction with clathrin-associated adaptor complexes.
Adaptor Protein Complex 1↗
Sequence requirements for the recognition of tyrosine-based endocytic signals by clathrin AP-2 complexes.
We recently determined that fusion proteins containing tyrosine-based endocytic signals bind to the mu 2 subunit of AP-2, the complex that drives clathrin coat formation and mediates endocytosis from the plasma membrane. Here we analyze the selectivity of peptide recognition by mu 2 and by AP-2 using combinatorial selection methods and surface plasmon resonance. Both mu 2 and AP-2 are shown to interact with various sequences of the form tyrosine-polar-polar-hydrophobic (Yppø) found on receptors that follow the clathrin pathway. The optimal sequence for interaction with mu 2 and with AP-2 has tyrosine as an anchor and prefers arginine at position Y + 2 and leucine at position Y + 3. In contrast, no preferred sequence is detected surrounding the Yppø signal, indicating that recognition of the Yppø endocytic signal does not require a prefolded structure. We conclude that sorting into the endocytic pathway is governed by a surprisingly simple interaction between the mu 2 chain and a tyrosine-containing tetrapeptide sequence.
Amino Acid Sequence↗
Swimming training improves brown-adipose-tissue activity in young and old mice.
The impairment of brown adipose tissue (BAT) thermogenic activity with aging has been well documented. The current study investigated the effect of swimming training on BAT activity in 2-month-old (young) and 26-month-old (old) male mice. The trained mice underwent a 6-week swimming program (1 h/day, 5 days/week) in water at 35-36 degrees C. Compared with young sedentary mice, the BAT-to-body mass ratio was markedly smaller in old sedentary mice, accompanied by the decreased amount of protein, whereas there was no significant difference in uncoupling protein (UCP) content, UCP mRNA expression, or guanosine 5'-diphosphate (GDP) binding (an index of UCP activity) between young and old mice. Meanwhile, the swimming training definitely increased BAT mass and its protein content in both the young and old mice, suggesting hypertrophy and hyperplasia. In addition, after the swimming training, the amounts of protein, UCP antigen, and GDP binding in the mitochondria recovered from BAT of both mice increased significantly as compared with the respective sedentary groups, while the expression of UCP mRNA did not vary substantially. These findings suggest that, irrespective of age, swimming training enhances the thermogenic activity and capacity in BAT of mice.
Adipose Tissue, Brown↗
Application of long-distance polymerase chain reaction to detection of junctional sequences created by chromosomal translocation in mature B-cell neoplasms.
Junctional sequences created by chromosomal translocations in mature B-cell neoplasms, which involve immunoglobulin gene loci (IG) and putative proto-oncogenes on reciprocal partner chromosomes, are unique to neoplastic cells characterized by particular histological and immunological phenotypes. To establish a rapid and sensitive method to detect neoplastic cells carrying a specific chromosomal translocation, we have developed a novel strategy based on long-distance polymerase chain reaction (LD-PCR) amplification. Genomic DNA was extracted from tumor cells carrying t(14;19)(q32;q13), t(8;14)(q24;q32), t(3;22)(q27;q11), t(2;3)(p12;q27), or t(3;14)(q27;q32). Thirty-two to 35-mer oligonucleotide primer pairs were designed to be complementary to exons or flanking sequences of the BCL3, c-MYC and BCL6 oncogenes, and to IG constant region genes. LD-PCR with a newly available Taq polymerase for longer product synthesis successfully amplified fragments representing BCL3/C alpha junctional sequences for t(14;19); c-MYC/C mu, c-MYC/C gamma, and c-MYC/C alpha for t(8;14); BCL6/C lambda for t(3;22); BCL6/C kappa for t(2;3); 5'-BCL6/C mu, and 5'-BCL6/C gamma for t(3;14). In Burkitt's lymphoma/leukemia, all materials in which c-MYC rearrangements were detectable by conventional Southern blot hybridization showed positive LD-PCR amplification. The sizes of the amplified fragments varied from 1.8 kb to 12 kb, and these were specific to each material. Serial dilution of tumor cells or DNA in negative materials demonstrated a single band on agarose gel electrophoresis stained with ethidium bromide at a level of sensitivity of 10(-3), and hybridization with radioactive probe improved the level by one order of magnitude (1 cell in 10(4)), indicating that this LD-PCR approach is a sensitive technique capable of detecting minimal residual disease. Thus, the present study provided a useful tool for diagnosis and subsequent management of B-cell neoplasms characterized by specific chromosomal translocations.
Base Sequence↗
Apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pig ovaries.
The porcine antral follicles, 3-6 mm in diameter, were dissected from the ovaries of mature pigs, and then granulosa and cumulus cells were isolated from each follicle. In atretic follicles, high activity of neutral Ca2+/Mg2+-dependent endonuclease and DNA ladder formation, estimated by electrophoresis, were noted in granulosa cells but not in cumulus cells. Extremely low activity of the endonuclease and no DNA ladder formation were observed in both types of cells obtained from healthy follicles. Moreover, apoptotic cells were observed histochemically among granulosa cells only. A good correlation (r = 0.987) between the endonuclease activity of granulosa cells and the progesterone/estradiol ratio of follicular fluid in each follicle was found. These results suggest that apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pigs.
Animals↗
Characteristics of vagal reflex-mediated tracheal response induced by bronchoconstriction in guinea pigs.
The reflex tracheal response induced by bronchoconstriction was investigated using a newly devised tracheo-bronchi preparation in anesthetized guinea pigs. Tracheal constriction and subsequent dilatation were observed in response to bronchoconstriction induced by the inhalation of 0.001-0.01% histamine and 0.003-0.03% acetylcholine. These tracheal responses were abolished by cervical vagotomy or treatment of the tracheal site with 1% tetrodotoxin. Tracheal constriction and dilatation were significantly inhibited by 0.1% atropine and 1% propranolol, respectively. When high tracheal tone was induced by 0.01% serotonin, the residual tracheal dilatation observed in the presence of propranolol was enhanced, while dilatation was completely inhibited by 1% hexamethonium. Dilatation was also suppressed by 1% N omega-nitro-L-arginine methyl ester (L-NAME) and 1% methylene blue. The tracheal constriction produced by bronchoconstriction was significantly enhanced by propranolol 2 mg/kg, i.v. and L-NAME 10 mg/kg, i.v. These results demonstrate that a vagally mediated reflex tracheal response (constriction followed by dilatation) is induced by bronchoconstriction in anesthetized guinea pigs. Cholinergic nerves may mediate the constriction, and adrenergic and nonadrenergic noncholinergic (NANC) inhibitory nerves may mediate the dilatation. Furthermore, NO may be involved in the NANC reflex tracheal dilatation.
Acetylcholine↗
B-cell epitopes in hypervariable region 1 of hepatitis C virus obtained from patients with chronic persistent hepatitis.
The hypervariable domain (HVR1) within the N-terminus of the E2 protein of hepatitis C virus (HCV) is known to be variable antigenically during the course of persistent infection. The aim of the study was to detect B-cell epitopes in HVR1 responsible for neutralizing HCV. The B-cell epitopes were analyzed using two series of synthetic peptides: 25 heptapeptides from the most common amino acids within 73 HVR1 sequences, and 216 heptapeptides, the sequences of which cover more than 65% of the 73 HVR1 sequences. Sera from three patients with chronic hepatitis C were tested for reactivity to the synthetic peptide sequences by enzyme-linked immunosorbent assay (ELISA). The post-interferon (IFN) serum of one patient who had a long-term response to treatment reacted specifically with 13 heptapeptides of 216 variable sequences of HVR1. Some of the amino acid sequences (amino acids 398, 399, 400, 404) of the heptapeptides were also found in those deduced from the nucleotide sequences of HCV genomes in the pre-IFN serum. The sera of the other two patients who did not respond to treatment did not react with the 13 heptapeptides. It is concluded that the B-cell epitopes in HVR1 may be relevant for eliminating viremia in the case of the patient who had a good response to treatment. These results suggest that the analysis of the B-cell epitopes recognized in HVR1 may be important in understanding the mechanism of persistent infection and progression of hepatitis.
Adult↗
A possible mechanism of heinz body hemolytic anemia induced by DQ-2511, a new gastroprokinetic drug, in dogs.
A previous study revealed that DQ-2511, a new gastroprokinetic drug, induced hemolytic anemia together with increased Heinz body formation, preceded by a marked decrease in erythrocyte reduced glutathione (GSH) content, after 2 weeks of dosing onward in dogs. In this study, the effect of DQ-2511 on erythrocytes in the early period of dosing, in comparison with that of beta-acetylphenylhydrazine (APHZ), was investigated to confirm the difference between this drug and APHZ in the mechanism of increased Heinz body formation. DQ-2511 and APHZ were administered orally to beagle dogs for 1 week at dose levels of 600 and 4 mg/ kg, respectively. Dogs receiving APHZ showed anemia after dosing for 7 days, together with an increase in methemoglobin and Heinz body formation after 3 days of dosing. In contrast, blood GSH, glutathione reductase, and gamma-glutamylcysteine synthetase were only slightly decreased after dosing for 7 days. In dogs treated with DQ-2511, erythrocyte GSH began to decrease after 1 day of treatment and was about 25% of the control value after 7 days; however, no changes were seen in blood glutathione reductase, GSH peroxidase, or gamma-glutamylcysteine synthetase level. Hepatic GSH was decreased slightly. In another experiment, SD rats were administered DQ-2511 and APHZ orally for 1 week at dose levels of 1600 and 15 mg/kg, respectively. Rats receiving DQ-2511 showed no anemia or any changes in erythrocyte GSH and Heinz body formation. In contrast, rats treated with APHZ showed a marked anemia and increases in Heinz body formation and erythrocyte GSH. These results demonstrate that DQ-2511 causes a marked decrease in GSH in dogs, resulting in Heinz body anemia, whereas APHZ induces Heinz body formation after a significant increase in methemoglobin, and suggest that impairment of the GSH redox cycle and synthetases of GSH are not involved in the decreased GSH after DQ-2511 treatment. This difference in effects on GSH content may indicate the existence of a species difference in the anemia induced by DQ-2511.
Anemia, Hemolytic↗
Superoxide dismutase derivative prevents oxidative damage in liver and kidney of rats induced by exhausting exercise.
To prevent oxidative tissue damage induced by strenuous exercise in the liver and kidney superoxide dismutase derivative (SM-SOD), which circulated bound to albumin with a half-life of 6 h, was injected intraperitoneally into rats. Exhausting treadmill running caused a significant increase in the activities of xanthine oxidase (XO), and glutathione peroxidase (GPX) in addition to concentrations of thiobarbituric acid-reactive substances (TBARS) in hepatic tissue immediately after running. There was a definite increase in the immunoreactive content of mitochondrial superoxide dismutase (Mn-SOD) 1 day after the running. Meanwhile, the TBARS concentration in the kidney was markedly elevated 3 days after running. The activities of GPX, and catalase in the kidney increased significantly immediately and on days 1 and 3 following the test. The immunoreactive content of Mn-SOD also increased 1 day after running. The exercise induced no significant changes in immunoreactive Cu, Zn-SOD content in either tissue. The administration of SM-SOD provided effective protection against lipid peroxidation, and significantly attenuated the alterations in XO and all the anti-oxidant enzymes, measured. In summary, the present data would suggest that exhausting exercise may induce XO-derived oxidative damage in the liver, while the increase in lipid peroxidation in the kidney might be the result of washout-dependent accumulation of peroxidised metabolites. We found that the administration of SM-SOD provided excellent protection against exercise-induced oxidative stress in both liver and kidney.
Animals↗
Bacteria closely resembling Helicobacter pylori detected immunohistologically and genetically in resected gallbladder mucosa.
A microorganism with close immunohistological and genetic resemblance to Helicobacter pylori was found in the resected gallbladder mucosa of a 41-year-old woman. The woman was admitted to hospital complaining of fever and right hypochondrial pain. Cholecystectomy was carried out under the diagnosis of gallstones and cholecystitis. A microorganism resembling H. pylori (stained with H&E, Giemsa, and Wartin-Starry) was detected incidentally on pathological examination. The microorganism was also positive for immunohistochemical staining. An amplification reaction was seen on genetic examination by the polymerase chain reaction (PCR) method (urease beta-genes). Our findings suggest that H. pylori may be present in tissues other than gastric mucosa.
Adult↗
Effects of aging and/or training on antioxidant enzyme system in diaphragm of mice.
We investigated the effects of aging and/or swimming training on the antioxidant enzyme system in diaphragm of mice. Young (2 months old) and old (26 months old) male mice were swimming-trained for 6 weeks (1 h/day, 5 days/week). Cu,Zn-Superoxide dismutase (Cu,Zn-SOD) activity was significantly upregulated with aging, and swimming training definitely enhanced the activity only in young mice. Neither aging nor swimming training had overt effect on Mn-SOD activity. Glutathione peroxidase activity in young mice was significantly increased after training, but not in old mice. Both of immunoreactive Cu,Zn-SOD and Mn-SOD were significantly increased with aging but were unaffected by swimming training. Consequently, physical training significantly enhanced the specific activity of Cu,Zn-SOD in young mice, but not in old mice. Meanwhile, swimming training significantly increased xanthine oxidase activity in both age groups, the extent of the increase being greater in old mice than in young mice. We concluded that the antioxidant enzyme system in mouse diaphragm trends to be upregulated with aging, but that swimming training improved the system only in young mouse diaphragm.
Aging↗
Treatment of traumatic radioulnar synostosis by excision, with interposition of a posterior interosseous island forearm flap.
A 21-year-old man had proximal radioulnar synostosis 10 months after fracture of the proximal radius and the ulna. The bony bridge was excised and a direct posterior interosseous island flap was interposed as a biological barrier. One year after surgery, the range of forearm rotation was 65 degrees. There was no radiographic evidence of recurrence.
Adult↗
Rearrangement of the BCL6 gene in B-cell lymphoid neoplasms: comparison with lymphomas associated with BCL2 rearrangement.
We report a series of B-cell neoplasms with regard to rearrangement of the BCL6 gene on chromosome band 3q27. Southern blot analysis using probes from the major translocation cluster (MTC) region of the BCL6 revealed rearrangement in 21/197 patients (10.7%) with B-cell neoplasms studied at presentation, and 11/25 patients (44%) first studied at relapse. In non-Hodgkin's lymphoma (NHL) studied at diagnosis, rearrangements of the BCL6 gene were not closely associated with a specific histopathologic subtype but distributed in subcategories in the Working Formulation. The incidence in follicular lymphoma was 12.1%, with significantly higher frequency in mixed and large cell subtypes, and that in diffuse aggressive lymphoma was 14.1%. Comigration analysis using probes from the immunoglobulin genes revealed association of the BCL6 gene with one of the three immunoglobulin loci in 9/25 cases analysed. A comparative study between NHL associated either with BCL2 or BCL6 rearrangement showed that advanced disease and bone marrow involvement were more frequent in BCL2(+) NHL. In contrast, extranodal involvement was more frequently observed in the BCL6(+) NHL. The survival curve of BCL6(+) NHL was characterized by a rapid decline followed by a plateau. Of the total of 32 BCL6(+) patients, six carried both BCL2 and BCL6 rearrangements; five of these six showed clinicopathological properties characteristic of follicular lymphoma, suggesting that the presence of the two genetic abnormalities does not necessarily have synergistic effects on malignant phenotypes. The high level of BCL6 expression in follicular lymphoma cell lines carrying a BCL2 rearrangement suggests that the deregulated BCL2 gene may have an effect on the development of genetic abnormalities of the BCL6 gene. The present study suggests that BCL6 gene rearrangement is primarily involved in large cell lymphoma irrespective of growth pattern of neoplastic cells, and that BCL6(+)BCL2(-) NHL could be curable with modern intensive chemotherapy.
Aged↗